main.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <stdio.h>
  20 #include <unistd.h>
  21
  22 #include "options.h"
  23 #include "defaults.h"
  24 #include "zones.h"
  25 #include "rules.h"
  26 #include "redirects.h"
  27 #include "forwards.h"
  28 #include "ipsets.h"
  29 #include "ubus.h"
  30
  31
  32 static bool print_rules = false;
  33 static enum fw3_family use_family = FW3_FAMILY_ANY;
  34
  35 static const char *families[] = {
  36         "(bug)",
  37         "IPv4",
  38         "IPv6",
  39 };
  40
  41 static const char *tables[] = {
  42         "filter",
  43         "nat",
  44         "mangle",
  45         "raw",
  46 };
  47
  48
  49 static struct fw3_state *
  50 build_state(void)
  51 {
  52         struct fw3_state *state = NULL;
  53         struct uci_package *p = NULL;
  54
  55         state = malloc(sizeof(*state));
  56
  57         if (!state)
  58                 error("Out of memory");
  59
  60         memset(state, 0, sizeof(*state));
  61         state->uci = uci_alloc_context();
  62
  63         if (!state->uci)
  64                 error("Out of memory");
  65
  66         if (uci_load(state->uci, "firewall", &p))
  67         {
  68                 uci_perror(state->uci, NULL);
  69                 error("Failed to load /etc/config/firewall");
  70         }
  71
  72         if (!fw3_find_command("ipset"))
  73         {
  74                 warn("Unable to locate ipset utility, disabling ipset support");
  75                 state->disable_ipsets = true;
  76         }
  77
  78         fw3_load_defaults(state, p);
  79         fw3_load_ipsets(state, p);
  80         fw3_load_zones(state, p);
  81         fw3_load_rules(state, p);
  82         fw3_load_redirects(state, p);
  83         fw3_load_forwards(state, p);
  84
  85         return state;
  86 }
  87
  88 static void
  89 free_state(struct fw3_state *state)
  90 {
  91         struct list_head *cur, *tmp;
  92
  93         list_for_each_safe(cur, tmp, &state->zones)
  94                 fw3_free_zone((struct fw3_zone *)cur);
  95
  96         list_for_each_safe(cur, tmp, &state->rules)
  97                 fw3_free_rule((struct fw3_rule *)cur);
  98
  99         list_for_each_safe(cur, tmp, &state->redirects)
 100                 fw3_free_redirect((struct fw3_redirect *)cur);
 101
 102         list_for_each_safe(cur, tmp, &state->forwards)
 103                 fw3_free_forward((struct fw3_forward *)cur);
 104
 105         uci_free_context(state->uci);
 106
 107         free(state);
 108
 109         fw3_ubus_disconnect();
 110 }
 111
 112
 113 static bool
 114 restore_pipe(enum fw3_family family, bool silent)
 115 {
 116         const char *cmd[] = {
 117                 "(bug)",
 118                 "iptables-restore",
 119                 "ip6tables-restore",
 120         };
 121
 122         if (print_rules)
 123                 return fw3_stdout_pipe();
 124
 125         if (!fw3_command_pipe(silent, cmd[family], "--lenient", "--noflush"))
 126         {
 127                 warn("Unable to execute %s", cmd[family]);
 128                 return false;
 129         }
 130
 131         return true;
 132 }
 133
 134 static bool
 135 family_running(struct list_head *statefile, enum fw3_family family)
 136 {
 137         struct fw3_statefile_entry *e;
 138
 139         if (statefile)
 140         {
 141                 list_for_each_entry(e, statefile, list)
 142                 {
 143                         if (e->type != FW3_TYPE_DEFAULTS)
 144                                 continue;
 145
 146                         return hasbit(e->flags[0], family);
 147                 }
 148         }
 149
 150         return false;
 151 }
 152
 153 static bool
 154 family_used(enum fw3_family family)
 155 {
 156         return (use_family == FW3_FAMILY_ANY) || (use_family == family);
 157 }
 158
 159 static bool
 160 family_loaded(struct fw3_state *state, enum fw3_family family)
 161 {
 162         return hasbit(state->defaults.flags, family);
 163 }
 164
 165 static void
 166 family_set(struct fw3_state *state, enum fw3_family family, bool set)
 167 {
 168         if (set)
 169                 setbit(state->defaults.flags, family);
 170         else
 171                 delbit(state->defaults.flags, family);
 172 }
 173
 174 static int
 175 stop(struct fw3_state *state, bool complete, bool restart)
 176 {
 177         int rv = 1;
 178         enum fw3_family family;
 179         enum fw3_table table;
 180
 181         struct list_head *statefile = fw3_read_statefile();
 182
 183         if (!complete && !statefile)
 184         {
 185                 if (!restart)
 186                         warn("The firewall appears to be stopped. "
 187                                  "Use the 'flush' command to forcefully purge all rules.");
 188
 189                 return rv;
 190         }
 191
 192         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 193         {
 194                 if (!complete && !family_running(statefile, family))
 195                         continue;
 196
 197                 if (!family_used(family) || !restore_pipe(family, true))
 198                         continue;
 199
 200                 info("Removing %s rules ...", families[family]);
 201
 202                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 203                 {
 204                         if (!fw3_has_table(family == FW3_FAMILY_V6, tables[table]))
 205                                 continue;
 206
 207                         info(" * %sing %s table",
 208                              complete ? "Flush" : "Clear", tables[table]);
 209
 210                         fw3_pr("*%s\n", tables[table]);
 211
 212                         if (complete)
 213                         {
 214                                 fw3_flush_all(table);
 215                         }
 216                         else
 217                         {
 218                                 /* pass 1 */
 219                                 fw3_flush_rules(table, family, false, statefile);
 220                                 fw3_flush_zones(table, family, false, statefile);
 221
 222                                 /* pass 2 */
 223                                 fw3_flush_rules(table, family, true, statefile);
 224                                 fw3_flush_zones(table, family, true, statefile);
 225                         }
 226
 227                         fw3_pr("COMMIT\n");
 228                 }
 229
 230                 fw3_command_close();
 231
 232                 if (!restart)
 233                         family_set(state, family, false);
 234
 235                 rv = 0;
 236         }
 237
 238         if (!restart &&
 239             !family_loaded(state, FW3_FAMILY_V4) &&
 240             !family_loaded(state, FW3_FAMILY_V6) &&
 241             fw3_command_pipe(false, "ipset", "-exist", "-"))
 242         {
 243                 fw3_destroy_ipsets(statefile);
 244                 fw3_command_close();
 245         }
 246
 247         fw3_free_statefile(statefile);
 248
 249         if (!rv)
 250                 fw3_write_statefile(state);
 251
 252         return rv;
 253 }
 254
 255 static int
 256 start(struct fw3_state *state, bool restart)
 257 {
 258         int rv = 1;
 259         enum fw3_family family;
 260         enum fw3_table table;
 261
 262         struct list_head *statefile = fw3_read_statefile();
 263
 264         if (!print_rules && !restart &&
 265             fw3_command_pipe(false, "ipset", "-exist", "-"))
 266         {
 267                 fw3_create_ipsets(state);
 268                 fw3_command_close();
 269         }
 270
 271         for (family = FW3_FAMILY_V4; family <= FW3_FAMILY_V6; family++)
 272         {
 273                 if (!family_used(family))
 274                         continue;
 275
 276                 if (!family_loaded(state, family) || !restore_pipe(family, false))
 277                         continue;
 278
 279                 if (!restart && family_running(statefile, family))
 280                 {
 281                         warn("The %s firewall appears to be started already. "
 282                              "If it is indeed empty, remove the %s file and retry.",
 283                              families[family], FW3_STATEFILE);
 284
 285                         continue;
 286                 }
 287
 288                 info("Constructing %s rules ...", families[family]);
 289
 290                 for (table = FW3_TABLE_FILTER; table <= FW3_TABLE_RAW; table++)
 291                 {
 292                         if (!fw3_has_table(family == FW3_FAMILY_V6, tables[table]))
 293                                 continue;
 294
 295                         info(" * Populating %s table", tables[table]);
 296
 297                         fw3_pr("*%s\n", tables[table]);
 298                         fw3_print_default_chains(table, family, state);
 299                         fw3_print_zone_chains(table, family, state);
 300                         fw3_print_default_head_rules(table, family, state);
 301                         fw3_print_rules(table, family, state);
 302                         fw3_print_redirects(table, family, state);
 303                         fw3_print_forwards(table, family, state);
 304                         fw3_print_zone_rules(table, family, state);
 305                         fw3_print_default_tail_rules(table, family, state);
 306                         fw3_pr("COMMIT\n");
 307                 }
 308
 309                 fw3_command_close();
 310                 family_set(state, family, true);
 311
 312                 rv = 0;
 313         }
 314
 315         fw3_free_statefile(statefile);
 316
 317         if (!rv)
 318                 fw3_write_statefile(state);
 319
 320         return rv;
 321 }
 322
 323 static int
 324 lookup_network(struct fw3_state *state, const char *net)
 325 {
 326         struct fw3_zone *z;
 327         struct fw3_device *d;
 328
 329         list_for_each_entry(z, &state->zones, list)
 330         {
 331                 list_for_each_entry(d, &z->networks, list)
 332                 {
 333                         if (!strcmp(d->name, net))
 334                         {
 335                                 printf("%s\n", z->name);
 336                                 return 0;
 337                         }
 338                 }
 339         }
 340
 341         return 1;
 342 }
 343
 344 static int
 345 lookup_device(struct fw3_state *state, const char *dev)
 346 {
 347         struct fw3_zone *z;
 348         struct fw3_device *d;
 349
 350         list_for_each_entry(z, &state->zones, list)
 351         {
 352                 list_for_each_entry(d, &z->devices, list)
 353                 {
 354                         if (!strcmp(d->name, dev))
 355                         {
 356                                 printf("%s\n", z->name);
 357                                 return 0;
 358                         }
 359                 }
 360         }
 361
 362         return 1;
 363 }
 364
 365 static int
 366 usage(void)
 367 {
 368         fprintf(stderr, "fw3 [-4] [-6] [-q] {start|stop|flush|restart|print}\n");
 369         fprintf(stderr, "fw3 [-q] network {net}\n");
 370         fprintf(stderr, "fw3 [-q] device {dev}\n");
 371
 372         return 1;
 373 }
 374
 375
 376 int main(int argc, char **argv)
 377 {
 378         int ch, rv = 1;
 379         struct fw3_state *state = NULL;
 380         struct fw3_defaults *defs = NULL;
 381
 382         while ((ch = getopt(argc, argv, "46qh")) != -1)
 383         {
 384                 switch (ch)
 385                 {
 386                 case '4':
 387                         use_family = FW3_FAMILY_V4;
 388                         break;
 389
 390                 case '6':
 391                         use_family = FW3_FAMILY_V6;
 392                         break;
 393
 394                 case 'q':
 395                         freopen("/dev/null", "w", stderr);
 396                         break;
 397
 398                 case 'h':
 399                         rv = usage();
 400                         goto out;
 401                 }
 402         }
 403
 404         if (!fw3_ubus_connect())
 405                 error("Failed to connect to ubus");
 406
 407         state = build_state();
 408         defs = &state->defaults;
 409
 410         if (!fw3_lock())
 411                 goto out;
 412
 413         if (optind >= argc)
 414         {
 415                 rv = usage();
 416                 goto out;
 417         }
 418
 419         if (use_family == FW3_FAMILY_V6 && defs->disable_ipv6)
 420                 warn("IPv6 rules globally disabled in configuration");
 421
 422         if (!strcmp(argv[optind], "print"))
 423         {
 424                 freopen("/dev/null", "w", stderr);
 425
 426                 state->disable_ipsets = true;
 427                 print_rules = true;
 428
 429                 rv = start(state, false);
 430         }
 431         else if (!strcmp(argv[optind], "start"))
 432         {
 433                 rv = start(state, false);
 434         }
 435         else if (!strcmp(argv[optind], "stop"))
 436         {
 437                 rv = stop(state, false, false);
 438         }
 439         else if (!strcmp(argv[optind], "flush"))
 440         {
 441                 rv = stop(state, true, false);
 442         }
 443         else if (!strcmp(argv[optind], "restart"))
 444         {
 445                 rv = stop(state, false, true);
 446                 rv = start(state, !rv);
 447         }
 448         else if (!strcmp(argv[optind], "network") && (optind + 1) < argc)
 449         {
 450                 rv = lookup_network(state, argv[optind + 1]);
 451         }
 452         else if (!strcmp(argv[optind], "device") && (optind + 1) < argc)
 453         {
 454                 rv = lookup_device(state, argv[optind + 1]);
 455         }
 456         else
 457         {
 458                 rv = usage();
 459         }
 460
 461 out:
 462         if (state)
 463                 free_state(state);
 464
 465         fw3_unlock();
 466
 467         return rv;
 468 }